U.S. patent number 6,158,765 [Application Number 09/146,593] was granted by the patent office on 2000-12-12 for occupant protection device for a motor vehicle.
This patent grant is currently assigned to Volkswagen AG. Invention is credited to Ruprecht Sinnhuber.
United States Patent |
6,158,765 |
Sinnhuber |
December 12, 2000 |
Occupant protection device for a motor vehicle
Abstract
An occupant protection device for a motor vehicle has at least
one inflatable airbag which, upon activation of at least one
associated gas generator passes through, leaves an exit opening in
the region in front of an occupant and enters the interior of the
motor vehicle. The airbag has a multi-chambered design and has at
least one inflatable thorax-protection gas chamber and a
head-protection gas chamber, which is connected to the said
thorax-protection gas chamber by gas-throughflow openings and, with
the airbag inflated, lies above the thorax-protection gas chamber,
the thorax-protection gas chamber is preceded by a smaller
inflatable gas prechamber, which is in connection with the gas
generator and can be inflated directly by the latter. The gas
prechamber is connected to the thorax-protection gas chamber of
gas-throughflow openings, so that the thorax-protection gas chamber
can be inflated indirectly by the gas generator via the gas
prechamber.
Inventors: |
Sinnhuber; Ruprecht (Gifhorn,
DE) |
Assignee: |
Volkswagen AG (Wolfsburg,
DE)
|
Family
ID: |
7841299 |
Appl.
No.: |
09/146,593 |
Filed: |
September 3, 1998 |
Foreign Application Priority Data
|
|
|
|
|
Sep 5, 1997 [DE] |
|
|
197 38 842 |
|
Current U.S.
Class: |
280/728.3;
280/729; 280/732 |
Current CPC
Class: |
B60R
21/233 (20130101); B60R 2021/23324 (20130101); B60R
2021/23332 (20130101) |
Current International
Class: |
B60R
21/16 (20060101); B60R 021/20 () |
Field of
Search: |
;280/729,730.1,728.3,732,743.2 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
2174607 |
|
Oct 1993 |
|
CA |
|
0483366 |
|
May 1992 |
|
EP |
|
0593172 |
|
Apr 1994 |
|
EP |
|
0769428 |
|
Apr 1997 |
|
EP |
|
2109637 |
|
Sep 1972 |
|
DE |
|
3743415 |
|
Jun 1988 |
|
DE |
|
4028715 |
|
Oct 1991 |
|
DE |
|
92114210 |
|
Mar 1993 |
|
DE |
|
4217177 |
|
Nov 1993 |
|
DE |
|
4231522 |
|
Mar 1994 |
|
DE |
|
4442543 |
|
Jan 1996 |
|
DE |
|
29517372 |
|
Mar 1996 |
|
DE |
|
19531667 |
|
Oct 1996 |
|
DE |
|
19538657 |
|
Apr 1997 |
|
DE |
|
29700804 |
|
May 1997 |
|
DE |
|
29707162 |
|
Jul 1997 |
|
DE |
|
29713111 |
|
Mar 1998 |
|
DE |
|
0132444 |
|
May 1989 |
|
JP |
|
3281460 |
|
Dec 1991 |
|
JP |
|
2265118 |
|
Sep 1993 |
|
GB |
|
9316902 |
|
Sep 1993 |
|
WO |
|
9625309 |
|
Aug 1996 |
|
WO |
|
Primary Examiner: Mai; Lanna
Attorney, Agent or Firm: Baker Botts L.L.P.
Claims
What is claimed is:
1. An occupant protection arrangement for a motor vehicle
comprising at least one inflatable airbag and at least one
associated gas generator, a cover having an exit opening in the
region of the motor vehicle in front of an occupant providing a
passage for the airbag to enter the interior of the motor vehicle,
the inflatable airbag comprising a plurality of chambers with at
least one thorax-protection gas chamber which can be inflated by a
gas generator and a head-protection gas chamber which is connected
to the thorax-protection gas chamber by gas-throughflow openings
and which, with the airbag inflated, lies above the
thorax-protection gas chamber, the thorax-protection gas chamber
being preceded by a smaller inflatable gas prechamber which is
connected to the gas generator and can be inflated directly by the
gas generator and wherein the gas prechamber is connected to the
thorax-protection gas chamber by gas-throughflow openings so that
the thorax protection gas chamber can be inflated indirectly by the
gas generator through the gas prechamber and wherein the exit
opening is closed by the cover when the airbag is not activated and
wherein, upon activation of the gas generator, the gas prechamber,
is inflated first and assists in removal of the cover and wherein
the exit opening is provided in a dashboard having a continuous,
jointless dashboard cover and a tear-open cover, including a
tear-open lever behind the tear-open cover which can be swivelled
downwardly, the tear-open lever being retained against the rear
side of the tear-open cover and, upon activation of the gas
generator by the inflatable prechamber, is swivelled downwardly and
thereby tears open the tear-open cover.
2. An occupant protection arrangement according to claim 1 wherein
in the inflated state of the inflatable airbag, the gas prechamber,
lies in the lower region against the thorax-protection gas chamber
without any supporting function for an occupant and wherein at
least two gas-throughflow openings are provided in a lateral upper
region of the gas prechamber with respect to the thorax-protection
gas chamber.
3. An occupant protection arrangement according to claim 1 wherein
the tear-open lever has an arcuate form with an approximately
horizontal first leg and an approximately vertical second leg in
normal position, the approximately horizontal first leg being
mounted at one end so that it can be swivelled and the second
approximately vertical leg engaging the rear side of the tear-open
cover and the dashboard cover having, in the region of the end of
the second, approximately vertical leg, a material weakening
providing a predetermined tear-open edge of the tear-open
cover.
4. An occupant protection arrangement according to claim 1 or claim
3 including at least two gas-throughflow openings in a lateral
upper region of the thorax-protection gas chamber with respect to
the head-protection gas chamber, and wherein the head-protection
gas chamber has a U-shape, which adjoins the thorax-protecting gas
chamber essentially in a transverse plane of the vehicle, and
wherein the U-leg ends of the head protection gas chamber point
downwardly and are connected in the region of the lateral
gas-throughflow openings to the thorax-protection gas chamber so
that the head-protection gas chamber does not have any neck bead in
the neck-impact region of an occupant.
5. An occupant protection arrangement according to claim 4, wherein
the beads of the U-legs extend upwardly and are thickened in the
region of the U-base in comparison with the U-legs as a protection
against sliding off in the event of oblique impact.
6. An occupant protection arrangement according to claim 1
including a second gas generator connected to the thorax-protection
gas chamber which can be activated with a time delay with respect
to the first inflating operation and enhances the supporting
function of the thorax-protection gas chamber by a second inflating
operation.
7. An occupant protection arrangement according to claim 6
including a second thorax-protection gas chamber for the second
inflating operation which is smaller than and is contained in the
first thorax-protection gas chamber.
Description
BACKGROUND OF THE INVENTION
The invention relates to an occupant protection device for a motor
vehicle having at least one inflatable airbag.
In the case of a generic occupant protection device for a motor
vehicle, as described in Canadian Patent Application No. 2,106,347,
use is made of an inflatable airbag which, upon activation of at
least one associated gas generator, leaves an exit opening in the
region in front of an occupant and enters the interior of the motor
vehicle. This airbag contains two chambers, a lower
thorax-protection gas chamber being inflatable by the gas
generator. Arranged above the thorax-protection gas chamber, with a
common intermediate wall, is a head-protection gas chamber, the
intermediate wall being provided with gas-throughflow openings,
through which the head-protection gas chamber can be inflated via
the thorax-protection gas chamber.
Following the activation of the gas chamber, a gas jet is directed
straight at the occupant, so that, immediately after leaving the
exit opening, the airbag shoots towards the occupant with
undesirably vigorous aggressiveness before the thorax-protection
gas chamber unfolds and the head-protection gas chamber is then
also inflated via the gas-throughflow openings. The completely
inflated airbag has a balloon-like shape, so that there is a
bead-like bulge also in the region where impact is made with the
neck. As a result, it is not possible to rule out the possibility
of the airbag moving under the chin of the occupant, in particular
at its connection between the thorax-protection gas chamber and the
head-protection gas chamber directed at the occupant, and of the
head of the occupant then being accelerated backwards, counter to
the direction of impact, with severe stressing of the cervical
spine.
In the case of another known occupant protection device for a motor
vehicle having an inflatable airbag in the region in front of an
occupant, described in German Gebrauchsmuster No. 297 00 804 the
said airbag is unsymmetrically shaped in the inflated state, in
such a way that there is a greater volume in the head-impact region
that in the thorax-impact region. Reference is generally made to
the possibility of subdividing such an airbag into a plurality of
chambers to be inflated, although nothing specific is stated in
this respect. Here too, an initial gas jet is directed from the gas
generator at the occupant with undesired aggressiveness.
Also known is a side-impact occupant protection device for a motor
vehicle, described in German Offenlegungsschrift No. 195 38 657, in
which an airbag with a thorax-protection gas chamber and a
head-protection gas chamber adjoining the latter leaves an exit
opening in a backrest. Here, the gas jet from the assigned gas
generator is directed in the longitudinal direction of the vehicle,
so that in the case of such a side airbag the problem of high
aggressiveness due to a gas jet directed at the occupant does not
occur.
It is also known to arrange a gas diffuser downstream of a gas
generator, as described in International Published Application No.
9625309, with which diffuser the radiating direction of the gas can
be influenced and a gas jet directed at an occupant can be divided
into different directions. Such a diffuser is an additional
component, which requires an installation space and which increases
the weight of the vehicle. In most cases such a diffuser cannot be
used for an additional function.
SUMMARY OF THE INVENTION
The object of the invention is to improve an occupant protection
device of the generic type to the extent that, while having a
simple design and a highly protective function, the aggressiveness
of an airbag is reduced.
This object is achieved by providing an occuput protection device
in which the thorax-protection gas chamber is preceded by a smaller
inflatable gas prechamber, which is in connection with the gas
generator and can be inflated directly by the latter. The gas
prechamber is connected to the thorax-protection gas chamber by
gas-throughflow openings, so that the thorax-protection gas chamber
can be inflated indirectly by the gas generator via the gas
prechamber.
This achieves the effect that the gas jet from the gas generator is
not directed straight at the occupant, but passes via the
deflecting gas-throughflow openings from the gas prechamber into
the thorax-protection gas chamber. As a result, the aggressiveness
of the airbag due to undesirably vigorous striking of an occupant
is reduced. There is no need for an additional diffuser part.
It is preferred in this case if, in the inflated state of the
airbag, the gas prechamber lies in the lower region against the
thorax-protection gas chamber, without any supporting function for
an occupant, so that a gas jet directed straight into the gas
prechamber does not cause any contact with an occupant. The at
least two gas-throughflow openings in this case lie in a lateral
upper region of the gas prechamber with respect to the
thorax-protection gas chamber. This represents a favourable
arrangement of the gas-throughflow openings for the avoidance of a
gas jet directed axially at the occupant.
In a way known per se, the exit opening for the airbag is closed by
a panel or cover when the airbag is not activated. It is
advantageous if, here, upon activation of the gas generator, the
first increase in volume of the gas prechamber can be used in an
additional function for removal of the panel or cover.
This function is particularly suitable in the case of an exit
opening in a dashboard with a continuous, jointless dashboard cover
and a tear-open cover. In this case, behind the tear-open cover
there is arranged a tear-open lever, which can be swivelled
downwards, is secured up against the rear side of the tear-open
cover and, upon activation of the gas generator by the inflatable
prechamber, is swivelled downwards and thereby tears open the
tear-open cover.
With suitable shaping of the tear-open cover, for example as an
angle lever, the effect is achieved that, following airbag
activation and removal of the exit-opening cover, no solid cover
parts are projected in an uncontrolled manner in the direction of
an occupant, since the tear-open lever is still held in the swivel
bearing and only relatively soft and compliant parts of the
dashboard cover protrude from the surface of the dashboard.
Altogether, the possibility of injury on the exit opening or from
cover parts is reduced as a result.
In a further development, it is proposed that at least two
gas-throughflow openings respectively lie in a lateral upper region
of the thorax-protection gas chamber with respect to the
head-protection gas chamber. The head-protection gas chamber has a
U-bead shape which adjoins the thorax-protection gas chamber
upwards, essentially in a transverse plane of the vehicle. The
U-leg ends in this case point downwards and are connected in the
region of the lateral gas-throughflow openings to the
thorax-protection gas chamber. In the case of this design, the
airbag, in particular the head-protection gas chamber, does not
have in the neck-impact region of an occupant any neck bead which
could pass under the chin of an occupant coming into forceful
contact, with the risk of cervical injuries. This design measure of
the airbag also reduces its aggressiveness, with a specific
influence brought to bear on the kinematics of the occupant.
In the event of oblique impact, there is the risk that an occupant
coming into contact with an activated airbag slides off to the
side, thereby reducing the protective function of the airbag.
Therefore, in a preferred development of the head-protection gas
chamber, it is proposed that the beads of the U-legs are drawn
upwards and thickened in the region of the U-base in comparison
with the latter, as a protection against sliding off in the event
of oblique impact.
Depending on the circumstances, it may be advantageous to use a
second or two-stage gas generator which, for a second, time-delayed
inflating operation, is connected to the thorax-protection gas
chamber or a further thorax-protection gas chamber. Such a second
inflating operation may be advantageous for improved support in the
event of very heavy impact and/or in the case of a very heavy
occupant and/or an "out of position" situation. These boundary
conditions for the triggering of a second inflating operation can
be detected by devices known per se, such as impact sensors and/or
occupant-identifying devices.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is explained in more detail with reference to the
drawings, in which:
FIG. 1 shows a diagrammatic representation of a dashboard cover
with a tear-open cover,
FIG. 2 shows a diagrammatic representation of an inflated
multi-chambered airbag,
FIG. 3 shows a diagrammatic representation of a first stage of
airbag activation,
FIG. 4 shows a diagrammatic representation of a second stage of
airbag activation,
FIG. 5 shows a diagrammatic representation of a third stage of
airbag activation, and
FIG. 6 shows a diagrammatic representation of a fourth stage of
airbag activation.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, an occupant protection arrangement 1 for a motor vehicle
is diagrammatically represented. This occupant protection device 1
has an airbag arrangement 3 with a multi-chambered airbag 2, which
can be activated by means of first and second gas generators 33 and
34. In the event of activation, the airbag 2 passes through an exit
opening, which can be formed in a dashboard 5 and is in the region
in front of an occupant, into the interior 4 of the motor vehicle.
The dashboard 5 is composed of a continuous, Pointless dashboard
cover 6 with a tear-open cover 7.
Arranged behind the tear-open cover 7 is an arcuate angle lever 9,
which can be swivelled downwards, as a tear-open lever. In the
position of rest 10, represented in FIG. 1, of the angle lever 9,
an approximately horizontal first angle leg 11 is mounted at the
end such that it can be swivelled, while a second, approximately
vertical angle leg 12 bears against the rear side 8 of the
tear-open cover 7. In the region of the free leg end of the second,
vertical angle leg 12, there is formed in the dashboard cover 6 a
material weakening as a predetermined tear-open edge 13 of the
tear-open cover 7.
The structural design of the multi-chambered airbag 2 is explained
in more detail below in connection with its four-stage activation
on the basis of FIGS. 2 to 6:
In the event of an accident and activation of the occupant
protection device 1, in the first stage of airbag activation,
firstly a gas prechamber 14 is inflated by means of the first gas
generator 33. On account of the increase in volume of the gas
prechamber 14, in the way diagrammatically represented in FIG. 3,
the angle lever 9 bearing with its vertical angle leg 12 against
the tear-open cover 7 is moved downwards out of its position of
rest 10, as is indicated by the arrow 15. The angle lever 9 thereby
exerts such a large force on the tear-open cover 7 that the
dashboard cover 6 tears in the region of the predetermined
tear-open edge 13 and the tear-open cover 7 is likewise moved
downwards. As a result, an exit opening for the airbag 2 is formed
in the dashboard cover 6, in the interior 4 of the motor vehicle in
the region in front of an occupant 16. The gas prechamber 14 for
this case does not perform any supporting function for the occupant
16.
As revealed by the diagrammatic representation of FIG. 2, the gas
prechamber 14 precedes a thorax-protection gas chamber 19 of the
airbag 2 and is connected to the latter via gas-throughflow
openings 17, 18. The two gas-throughflow openings 17, 18 are in
this case respectively arranged in a lateral, upper region of the
gas prechamber 14 with respect to the thorax-protection gas chamber
19. Consequently, the thorax-protection gas chamber 19 can be
inflated indirectly by the first gas generator 33 via the gas
prechamber 14. As a result, as diagrammatically represented in FIG.
4, in the second stage of airbag activation, the thorax-protection
gas chamber 19 is inflated for thorax protection of the occupant
16, without a gas jet acting directly on the said occupant.
As can be seen from FIG. 2, the thorax-protection gas chamber 19 is
connected to a head-protection gas chamber 23, which can be
inflated via two gas-throughflow openings 20, 21. These
gas-throughflow openings 20, 21 are respectively arranged in a
lateral, upper region of the thorax-protection gas chamber 19 with
respect to the head-protection gas chamber 23. The head-protection
gas chamber 23 is likewise inflated indirectly by the first gas
generator 33. As a result, as can be seen from the diagrammatic
representation of FIG. 5, in the third stage of airbag activation,
the head-protection gas chamber 23 is inflated via the
thorax-protection gas chamber 19 for head protection of the
occupant 16, likewise without a gas jet acting directly on the said
occupant.
As FIG. 2 reveals, the head-protection gas chamber 23 has a U-bead
shape, the U-leg ends 24, 25 of which point downwards and are
connected to the thorax-protection gas chamber 19 in the region of
the lateral gas-throughflow openings 20, 21. As a result, the
head-protection gas chamber 23 does not have in the neck-impact
region 26 of the occupant 16 any neck bead. Furthermore, in the
region of the U-base 29 of the head-protection gas chamber 23,
beads 27, 28 of the U-legs 30, 31 are drawn upwards and thickened
in comparison with this U-base 29, and thus serve as a protection
against sliding off in the event of oblique impact.
In the fourth stage of airbag activation, a second
thorax-protection gas chamber 32, which is preferably smaller and
is contained in the first thorax-protection gas chamber 19, is
inflated by the second gas generator 34 in a second inflating
operation with a time delay with respect to the first inflating
operation. As represented merely diagrammatically in FIG. 6, this
second thorax-protection gas chamber 32 enhances the supporting
function of the first thorax-protection gas chamber 19, for example
in the event of very heavy impact and/or in the case of a very
heavy occupant 16 and/or an "out of position" situation of the
occupant 16. The triggering of the second inflating operation in
this case takes place, for example, with the aid of impact sensors
and/or occupant-identifying devices.
* * * * *